An aromatic polycarbonate resin is excellent in impact resistance, heat resistance, rigidity, dimensional stability, and the like. An aromatic polycarbonate resin therefore has been widely used in various applications, such as electric apparatuses, communication apparatuses, precision machines, automobile components, and the like.
Various studies have been made about compounding an aromatic polycarbonate resin with a polyester resin such as a poly(ethylene terephthalate) for improving chemical resistance of an aromatic polycarbonate resin. Patent Document 1 discloses a thermoplastic resin composition which has a high chemical resistance while maintaining a good fluidity and which is excellent in impact resistance, heat resistance, rigidity, and thermal stability. The thermoplastic resin composition includes an aromatic polycarbonate having a viscosity average molecular weight of 16,000 to 23,000, a poly(ethylene terephthalate) resin which has an intrinsic viscosity value (IV value) of 0.45 to 0.57 dl/g and a terminal carboxyl group amount of 20 to 35 eq/ton, and a rubber type polymer.
Patent Document 2 discloses an aromatic polycarbonate resin having fluidity, rigidity, heat resistance, impact resistance, chemical resistance, and fatigue resistance respectively in good balance. The aromatic polycarbonate resin composition includes an aromatic polycarbonate resin, a poly(butylene terephthalate) resin, and a rubber type polymer. The poly(butylene terephthalate) resin has a titanium compound content more than 1 to 75 ppm expressed as a content of a titanium atom, and has a terminal carboxyl group concentration of 39 μeq/g or less.
A housing of a portable terminal including a mobile phone, a smart phone, a portable game machine, and an electronic notebook has been required to reduce its size, thickness, weight, and cost, so that housings formed from thermoplastic resins have been widely used.
A thermoplastic resin composition used as a molding material for housing of a portable terminal requires having the following characteristics.    (1) Moldability having excellent fluidity and being capable of molding even a housing having a small wall thickness and a complicated shape with high accuracy. A short molding cycle is also required for improving productivity of a housing.    (2) Impact resistance by which no breakage occurs when a molded article is dropped by mistake in handling. The impact resistance is required to be excellent not only at an ordinary temperature but also in a low-temperature environment such as in winter or in a cold area.    (3) Chemical resistance by which no degradation occurs even if a cosmetic, a detergent, a chemical, and/or the like is adhered to a molded article.    (4) Durability against ambient environment in which a molded article is used. In particular, a high heat resistance under high temperature conditions in midsummer (such as an inside of an automobile parked under scorching sun) is required. The heat resistance is also required to satisfy the durability against baking in a coating operation. A sufficiently high heat resistance is also required even when a molding material is exposed to a long-term thermal history during molding. This heat resistance is referred to as the “residence heat resistance” in the present specification.